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7. FAULT FINDING – Page 20
SYMPTOM
POSSIBLE CAUSE
SOLUTION
LOW WATER TEMPERATURE
1.
Temperature selector set to ‘-‘.
1.
Turn selector to ‘+’.
2.
Gas pressure too low.
2.
Check and clean gas filter, also
check gas inlet pressure.
3.
Faulty diaphragm. Will also cause a
high water rate.
3.
Replace the diaphragm
assembly - Part No 10/17534.
4.
Automatic gas valve push rod sticking.
May also cause a high water rate.
4.
Dismantle dean and regrease
using Dow Corning 111 silicone
grease. Handle the push rod with
care, do not bend.
5.
Slow ignition screw incorrectly set. Will
also cause a high water rate.
5.
See Fig. 16 for the position of
the screw. Turning the screw
clockwise delays the ignition,
anti-clockwise advances the
ignition. The screw should be set
2 full turns out (anti clockwise)
from the fully in position. When
correct the burner ignition should
be smooth and quiet when a hot
water outlet is opened.
NOISY HEATER
1.
Heat exchanger scaled. Ultimately this
will cause the heat exchanger fins to
discolour and buckle.
1.
Descale or replace - Part No
10/1 7558.
2.
Noisy ignition could be caused by
incorrect setting of the slow ignition
screw.
2.
See Fig. 16 for the position of
the screw. Turning the screw
clockwise delays the ignition,
anti-clockwise advances the
ignition. The screw should be set
2 full turns out (anti-clockwise)
from the fully in position. When
correct the burner ignition should
be smooth and quiet when a hot
water outlet is opened.
3.
Reduced pilot rate caused by dirt.
3.
Clear injector by blowing through
or replace with pilot injector Part
No 19/12690. Also clean the lint
filter located at the base of pilot
tube.
4.
Burner aeration ports and main flame
ports blocked.
4.
Carefully clean the burners with
a vacuum cleaner.